Tree Rose Failure: When the Rootstock Takes Over

A Knock Out tree rose, staked too tightly until the stake nearly severed the trunk, has stopped blooming. Meanwhile, two long, straight shoots have emerged from the base. Can these become a new Knock Out bush?

How Tree Roses Are Constructed

Standard tree roses are created by growing a Rugosa rose to the desired height (typically three feet), rubbing off all side shoots to form a clean trunk, then budding a modern rose (like Knock Out) onto the top. The growth emerging from the base is the Rugosa rootstock, not the grafted Knock Out.

Options for the Gardener

If the top has died or is failing, the tree rose cannot revert to a Knock Out bush. However, the Rugosa shoots can be developed into a Rugosa shrub by cutting the main stem off just half an inch above the new shoots. This yields a hardy, vigorous Rugosa rose—but not the original Knock Out variety.

For a true Knock Out replacement, a new grafted tree rose or own-root Knock Out plant would be needed.